Neonatal respiratory insufficiency due to centronuclear myopathy.

Two neonates showing generalized hypotonia, weakness of limbs, trunk, and oral musculature died because of muscular respiratory distress. The diagnosis of centronuclear (or myotubular) myopathy was established by histological and histochemical techniques. The genetic situation and routine laboratory data including electromyography were compared with similar cases in the literature; findings were inconclusive with respect to this diagnosis. These results indicate the need for a muscle biopsy and the use of histochemical stainings and/or electronmicroscopical investigation for a proper diagnosis in hypotonic newborns under respiratory distress after exclusion of etiologies other than neuromuscular diseases. Still the diagnosis of centronuclear myopathy in a neonate does not allow a precise prognosis. Increased awareness of this disorder and adequate diagnostic workup is needed in order to extend our understanding and to clarify the prognosis.